Sudden Infant Death Syndrome (SIDS) is, in most western countries, the leading cause of postneonatal mortality, but the identification of valid and unique risk factors for this cause of death has been thwarted by limitations of available descriptive information on demographic, gestational, maternal, labor/delivery, and early neonatal factors. Information of this nature exists within the National Collaborative Perinatal Project (NCPP) of the National institute of Neurologic Communicative Disorders and Stroke, NIH. This current application proposes, using the NCPP available dataset, to identify from the broad array of maternal and infant variables, risk factors associated with SIDS and to develop a risk prediction model using multivariate techniques. Deaths ascribable to SIDS have been identified and confirmed previously. Estimates of risk (odds ratios) will be derived with matched sets of cases and living controls and non-living controls. A logistic model, using all available data from within the cohort, will then be developed in order to determine the risk associated with single and joint exposure to the SIDS risk factors identified in the primary analyses.